The present invention relates generally to a blank from which a lens pattern is cut, and deals more specifically with such a blank that is connectable to other like blanks to form a chain for continuous feeding to a lens pattern generator.
Eyeglass frame manufacturers conventionally provide a lens pattern having the size and shape of the frame lens opening for each eyeglass frame style produced by the manufacturer. An optician and/or lens grinder often maintains an inventory of lens patterns covering all of the different eyeglass frame styles sold or serviced. In one business practice in which an inventory is kept, an appropriate pattern is selected from the inventory and is used in cooperation with a lens grinding apparatus to contour the periphery of an optical lens to the size and shape of the lens opening of the associated frame.
The proliferation of different eyeglass frame styles has greatly increased inventory requirements both in terms of the large number of different lens patterns and the space requirements necessary to store the patterns. In addition, the number of manufacturers of eyeglass frames has substantially increased during recent years adding to the number of different patterns required in inventory.
In addition to the problems associated with keeping an inventory and the associated storage space requirements is the problem associated with the suitability of using a pattern from inventory for all eyeglass frames of one style. The advent of a large number of manufacturers has increased competition in the eyeglass frame market and has, in many instances, resulted in frames of lower cost and lower quality. Many times, the size and shape of the frame lens opening associated with a frame style is not consistent from frame-to-frame. Consequently, an optical lens peripherally contoured or edged using the lens pattern supplied for a given frame style may not properly fit the lens opening of an actual frame of that style.
Yet another problem occasionally associated with the business practice of using lens patterns supplied by the eyeglass frame manufacturers, especially in instances where the frames are manufactured off-shore and imported to the United States is that the patterns may become misdirected when shipped separately or may not be included with the frames when the patterns and frames are shipped together. If a pattern corresponding to a lost pattern is not in inventory, the frame generally cannot be easily fitted with an optical lens and consequently the optician and/or lens grinder incurs substantial incovenience and additional expense in fitting the optical lens to the frame.
Yet another problem sometimes associated with the use of a lens pattern is the pattern may become worn through usage and thereafter be an inaccurate guide. A lens cut from such a worn pattern may not properly fit its intended frame lens opening or may fit loosely and eventually fall out subjecting it to scratches, loss or breakage.
A solution to the above-mentioned problems associated with using a lens pattern for edging eyeglass lenses is to not supply any such patterns in advance of their need, but rather to generate such a pattern immediately before the edging operation by tracing the lens opening of the actual frame with which it is to be used. Tracing apparatus for generating information representative of the size and shape of a frame lens opening is disclosed in a copending application filed concurrently herewith entitled APPARATUS FOR TRACING THE LENS OPENING IN AN EYEGLASS FRAME Ser. No. 896624 and assigned to the same assignee as the present invention. The information provided by this tracing apparatus may then be utilized by a lens pattern generator to produce a pattern. Such a lens pattern generator is disclosed in another copending application filed concurrently herewith entitled "METHOD AND APPARATUS FOR MAKING A PATTERN FOR A LENS OPENING IN AN EYEGLASS FRAME Ser. No. 896615, Know'll U.S. Pat. No. 4,711,035" and assigned to the same assignee as the present invention.
To have a lens pattern for each of the eyeglass frames to be fitted during the course of a busy work day, it is necessary to produce the patterns in a relatively short time. Apparatus for producing large numbers of differently shaped patterns must necessarily have a high speed, be accurate and be as automated as possible. Consequently, a minimum amount of operator intervention in producing each pattern is a desirable goal. One way to achieve this, at least in part, is to provide a blank from which a lens pattern may be cut to the desired size and shape and having characteristics and features for automatic feeding to and positioning by a lens pattern generator such as described by the above-identified patent application, or similar apparatus, that cuts or otherwise forms the blank to the size and shape of the desired lens pattern.
An object of the present invention is therefore, to provide a blank, having the foregoing features, from which a lens pattern may be cut.
Another object of the invention is to provide a blank having features that permit its automatic feeding to a lens pattern generator.
A further object of the present invention is to provide a blank that may be interconnected to other like blanks to form a compactly packagable chain for high speed feeding to a lens pattern generator, and which blank once loaded in the generator is easily separable from the chain after it reaches its cutting station.